Cu-Mn-I Solid Solution Thin Films: Preparation and Control of p-type Transparent Conductive Properties

doi:10.15541/jim20250022

Abstract

Abstract:

In the field of optoelectronic devices, p-type transparent semiconductor materials with controllable electrical properties hold significant application value. CuI, as a representative material, still faces considerable technical challenges in terms of preparation processes and doping control. This study successfully developed a new p-type transparent semiconductor material with adjustable electrical properties through manganese cation doping, offering a new approach for the advancement of transparent electronics. The Cu_1-_xMn_xI solid solution film, prepared via reactive magnetron sputtering, exhibits unique performance advantages. Firstly, the material can be fabricated at room temperature while maintaining excellent visible light transparency. Secondly, as the manganese doping concentration (x) increases, the grain size of the film gradually decreases, and pronounced crystal cluster aggregation is observed at higher doping concentrations. X-ray photoelectron spectroscopy analysis reveals that manganese ions in the film exist in a mixed valence state of Mn²⁺ and Mn³⁺. Electrical performance characterization shows that the resistivity of the film can be tuned over two orders of magnitude, ranging from 0.017 to 2.5 Ω·cm, while the hole carrier concentration remains stable at a high order of magnitude of 10¹⁸-10¹⁹ cm^-3. Unlike the n-type doping behavior observed in traditional semiconductors, introduction of high-valent manganese ions does not significantly affect the p-type conductivity of the material. This is likely due to the partially localized electronic state formed when manganese replaces cuprous ions. This discovery suggests that the hole conductivity of CuI semiconductors is not easily affected by high-valent manganese ion doping, enabling a wide range of compositional adjustments while maintaining stable p-type conductivity. This study provides a valuable material basis for the development of CuI-based multifunctional transparent electronic devices.

Key words: Cu_1-_xMn_xI, transparent p-type semiconductor, controllable p-type resistivity

CLC Number:

TQ174

WANG Liangjun, OUYANG Yuzhao, ZHAO Junliang, YANG Chang. Cu-Mn-I Solid Solution Thin Films: Preparation and Control of p-type Transparent Conductive Properties[J]. Journal of Inorganic Materials, 2025, 40(9): 1022-1028.

Figures/Tables 5

Fig. 1 SEM images of Cu1-xMnxI thin films (a-e) and elemental distribution mappings of Cu0.95Mn0.05I thin films (f-h)

Fig. 2 Crystal structure analyses of Cu1-xMnxI thin films (a) XRD patterns; (b) Localized magnified patterns of diffraction peak (111); (c) Schematic diagram of manganese ions replacing copper ions; (d) Dependence of grain size and FWHM on x

Fig. 3 Analyses of optical bandgap of Cu1-xMnxI thin films (a) UV-Vis transmission spectra; (b) Tauc plots; (c) Dependence of Eg on x; (d) Schematic diagram of the influence of donor energy levels on Eg. Colorful figures are available on website

Fig. 4 XPS spectra of Cu1.00I and Cu0.95Mn0.05I thin films (a) XPS survey spectra; (b) High-resolution Mn2p XPS spectra of Cu0.95Mn0.05I films; (c, d) High-resolution I3d (c) and Cu2p (d) XPS spectra of Cu1.00I and Cu0.95Mn0.05I thin films

Fig. 5 Dependence of x on resistivity, carrier density, and mobility in Cu1-xMnxI thin films

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